In this guide, I will briefly describe my favorite class, Vanguard, and my strategy that goes along with it in Mass Effect 2.
The Vanguard. One of the most difficult, yet rewarding, classes to be used in Mass Effect 2. The Vanguard class is a hybrid class that combines the combat techniques of a Soldier and an Adept class. It is a class that requires you to be up close and personal with your opponent. Utilizing both weapons and biotic powers effectively is key to being a fantastic Vanguard. Weapons available to this class are heavy pistols, submachine guns, and shotguns (along with the additional heavy weapon). A number of biotic powers are used as well. Just to name a few: Pull, Slam, Shockwave, Barrier, and it's exclusive power, Charge. All of these powers grant you a distinct advantage on the battlefield. A quick and efficient powerhouse, Vanguards are a deadly force to face.
Having chosen a Vanguard in almost every playthrough I've done in Mass Effect 2 (as well as the first Mass Effect), I've developed quite a few strategies when fighting an enemy. Whether it's a Blue Sun gang member, a charging Krogan, or a Collector Drone, only two things apply when being a Vanguard: efficiency and power. It takes quick thinking and the right biotics to be a successful Vanguard. Whenever I'm faced with a large amount of enemies in front of me, I typically wait until the perfect moment to do maximum damage. For example, if 4 or 5 Eclipse mercenaries are closing in on me, I wait until they are close enough to hit them with a Pull Field power. This instantly lifts all of them into the air, leaving them helpless. Since the biotic Pull has a fast recharge time, it leaves me with ample time to close in on them and finish them off with a couple shotgun rounds of a deadly biotic Charge. This method is extremely effective if you're dealing with large amounts of fire. NOTE: Make sure you bring their shields or barriers down first with a heavy pistol or submachine gun, otherwise the Pull effect won't work as well.
That was just one of my general strategies. There are many that you can do, or create your own! Being a Vanguard is dangerous, but the reward of your combative decisions make it that much sweeter if you "pull" them off (pun intended). Once you get the hang of when to shoot, when to throw a shattering Shockwave, or when to obliterate your opponent with a Charge, you'll absolutely love the Vanguard Class. Remember, efficiency and power is key.